A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a needle, or via fingerprick. Multiple tests for specific blood components (such as a glucose test or a cholesterol test) are often grouped together into one test panel called a blood panel or blood work.
Upper Air Troughs. When the height contours bend strongly to the south, (as in the diagram below), it is called a TROUGH. Strong troughs are typically preceded by stormy weather and colder air at the surface. Here is an example of a trough in an upper-level height field (red contours).
Show More. An HVAC air handling unit (also called an AHU) is the indoor part of your heating and cooling system. An air handler circulates both cool and hot air, depending on the season. When properly matched with a heat pump or air conditioner, an air handler will help you maximize the overall efficiency of your HVAC system.